Harmful Algal Blooms (HABs) and desalination

538 Pages·2017·27.68 MB·English

Manuals and Guides 78
Harmful Algal Blooms (HABs)
and Desalination: A Guide to
Impacts, Monitoring, and Management

Edited by:
Donald M. Anderson, Siobhan F.E. Boerlage, Mike B. Dixon
UNESCO
Manuals and Guides 78
Intergovernmental Oceanographic Commission

Harmful Algal Blooms (HABs) and Desalination: A
Guide to Impacts, Monitoring and Management

Edited by:

Donald M. Anderson*
Biology Department, Woods Hole Oceanographic Institution
Woods Hole, MA 02543 USA

Siobhan F. E. Boerlage
Boerlage Consulting
Gold Coast, Queensland, Australia

Mike B. Dixon
MDD Consulting, Kensington
Calgary, Alberta, Canada

*Corresponding Author’s email: [email protected]

UNESCO 2017
IOC Manuals and Guides, 78
Paris, October 2017
English only
The preparation of this manual was supported by the U.S. Agency for International
Development (USAID) through a contract to the Middle East Desalination Research Center
(MEDRC). Additional support for publishing came from the Intergovernmental
Oceanographic Commission (IOC) of UNESCO.
The Manual was prepared with support from multiple programs and agencies, including the
United States Agency for International Development, the Middle East Desalination Research
Center, and the Intergovernmental Oceanographic Commission. Neither these sponsors nor
the editors and contributing authors guarantee the accuracy or completeness of any
information published herein, and neither these sponsors nor the editors and contributing
authors shall be responsible for any errors, omissions, or damages arising out of the use of
this information. This work is published with the understanding that the sponsors, editors,
and contributing authors are supplying information but are not attempting to render
engineering or other professional services. If such services are required, the assistance of
appropriate professionals should be sought. Furthermore, the sponsors, editors, and authors
do not endorse any products or commercial services mentioned in the text.
The designations employed and the presentation of the material in this publication do not
imply the expression of any opinion whatsoever on the part of the Secretariats of UNESCO
and IOC concerning the legal status of any country or territory, or its authorities, or
concerning the delimitation of the frontiers of any country or territory.
For bibliographic purposes this document should be cited as follows:
Anderson D. M., S. F. E. Boerlage, M. B. Dixon (Eds), Harmful Algal Blooms (HABs) and
Desalination: A Guide to Impacts, Monitoring and Management. Paris, Intergovernmental
Oceanographic Commission of UNESCO, 2017. 539 pp. (IOC Manuals and Guides No.78.)
(English.) (IOC/2017/MG/78).
Cover photo: Chlorophyll concentrations captured by the MODIS Aqua sensor (NASA) from
February 6, 2016, showing typical bloom patterns for the Arabian Gulf, Sea of Oman region,
with low chlorophyll (dark blue) away from the coasts and high chlorophyll (orange and red)
in complex patches and filaments, particularly around the Arabian Peninsula. The patterns are
caused by surface transport and concentration of a harmful Cochlodinium bloom that is
widely dispersed in response to surface currents and eddies. (Courtesy of R. Kudela,
University of California, Santa Cruz and the National Aeronautics and Space Administration
(NASA). Back cover photo: Foaming observed in the rapid mix basins during pretreatment
at Tampa Bay Seawater Desalination Plant during an algal bloom event (Courtesy of Nikolay
Voutchkov, Water Globe Consultants, LLC 2009).

First published in 2017 by the United Nations Educational,
Scientific, and Cultural Organization
7, Place de Fontenoy, 75732 Paris 07 SP

© UNESCO 2017

Printed in Denmark
FOREWORD
Coastal development is progressing at a rapid pace and coastal populations are increasingly
vulnerable to sea-level rise, tsunamis, coastal erosion, storms, and other adverse
environmental phenomena. One of the objectives of the Intergovernmental Oceanographic
Commission of UNESCO (IOC) is to facilitate safety and security of people in the coastal
zone and at sea. For example, the IOC operates a quasi-global tsunami warning system and
strives to enable efficient coastal zone management that is fully informed of all major coastal
risks.
In a number of coastal countries with dry climates, the demands for food and water are to a
significant extent supported by seawater desalination activities. One marine hazard that is a
threat to the large and rapidly expanding desalination industry is harmful algal blooms
(HABs). The harm comes in part from algal production of neurotoxins as well as bad taste
and odor and skin-irritating compounds that may persist in the treated water. Another major
concern is the organic material produced by some algal blooms, as these compounds can clog
intake filters and foul membrane surfaces, greatly compromising plant operations. Expansion
of harmful algal events is inevitable given global trends in population, agriculture,
development and climate. With the already observed increase in the number of toxic and
harmful blooms, the resulting economic losses, the types of resources affected, and the
number of toxins and toxic species reported, HAB problems can only be expected to increase.
For more than 20 years IOC has offered leadership in capacity building and international
research cooperation in relation to harmful algae. The overall goal of the IOC Harmful Algal
Bloom Programme is to foster the effective management of, and scientific research on, HABs
in order to understand their causes, predict their occurrences, and mitigate their effects. The
programme activities include provision of information and expertise, training, and research to
improve understanding of harmful algae ecology. The design of efficient and effective HAB
monitoring programmes can minimize the impacts of HABs on drinking water and seafood
quality, thereby protecting public health and resources.
Despite the overall progress of HAB research, desalination plant operators and those who
design plants or advise plant managers have thus far had very little information and guidance
on how to manage and mitigate the effects of harmful algae on desalination operations. To
meet their needs, the Intergovernmental Panel on Harmful Algal Blooms (IPHAB)
established an international Task Team to address the effects of harmful algae on
desalination. The group was heavily involved in the organization of two major conferences
on the subject and was successful in reaching out to the expert community. The time has now
come to combine experience and publish this book: Harmful Algal Blooms (HABs) and
Desalination: A Guide to Impacts, Monitoring and Management.
The IOC is pleased to be a co-sponsor of this important effort and hopes this Guide can help
address the practical issues that harmful algae pose to desalination. At the same time the need
for continuing targeted research in this topic area must also be stressed. Improved HAB
forecasts for desalination plants will rely on improved coastal models, in combination with in
situ observations that can detect and quantify HAB cells and toxins, or satellite remote
sensing data to characterize the spatial extent and density of the blooms. A collaborative
program can be envisioned involving multiple desalination plants with the aim of
transitioning pilot HAB forecasting systems (like those described in this Guide) into
operational systems.
Vladimir Ryabinin
Executive Secretary, IOC
3
Acknowledgements

The Editors would like to thank the following people who assisted in the preparation of this
manual. These include: Shannon McCarthy for her efforts to initiate and obtain funding for
this project, Kevin Price for his administrative work, Karen Steidinger for reviewing the algal
species descriptions, Judy Kleindinst for major editorial and layout support, and Henrik
Enevoldsen for publication assistance.

4
PREFACE
Arid countries throughout the world are heavily reliant on seawater desalination for their
supply of drinking and municipal water. The desalination industry is large and rapidly
growing, approaching more than 20,000 plants operating or contracted in greater than 150
countries worldwide and capacity projected to grow at a rate of 12% per year for the next
several decades (http://www.desaldata.com; 2016). Desalination plants are broadly
distributed worldwide, with a large and growing capacity in what will be referred to as the
“Gulf” region throughout this manual. Here the Gulf refers to the shallow body of water
bounded in the southwest by the Arabian Peninsula and Iran to the northeast. The Gulf is
linked with the Arabian Sea by the Strait of Hormuz and the Gulf of Oman to the east and
extends to the Shatt al-Arab river delta at its western end.
One of the operational challenges facing the industry is also expanding globally – the
phenomena termed harmful algal blooms or HABs. Blooms are cell proliferations caused by
the growth and accumulation of individual algal species; they occur in virtually all bodies of
water. The algae, which can be either microscopic or macroscopic (e.g., seaweeds) are the
base of the marine food web, and produce roughly half of the oxygen we breathe. Most of the
thousands of species of algae are beneficial to humans and the environment, but there are a
small number (several hundred) that cause HABs. This number is vague because the harm
caused by HABs is diverse and affects many different sectors of society (see Chapter 1).
HABs are generally considered in two groups. One contains the species that produce potent
toxins (Chapter 2) that can cause a wide range of impacts to marine resources, including mass
mortalities of fish, shellfish, seabirds, marine mammals, and various other organisms, as well
as illness and death in humans and other consumers of fish or shellfish that have accumulated
the algal toxins during feeding. The second category is represented by species that produce
dense blooms - often termed high biomass blooms because of the large number of cells.
Cells can reach concentrations sufficient to make the water appear red (hence the common
term “red tide”), though brown, green and golden blooms are also observed, while many
blooms are not visible.
In this manual, we define toxic algae as those that produce potent toxins (poisonous
substances produced within living cells or organisms), e.g., saxitoxin. These can cause
illness or mortality in humans as well as marine life through either direct exposure to the
toxin or ingestion of bioaccumulated toxin in higher trophic levels e.g. shellfish. Non-
toxic HABs can cause damage to ecosystems and commercial facilities such as desalination
plants, sometimes because of the biomass of the accumulated algae, and in other cases due to
the release of compounds that are not toxins (e.g., reactive oxygen species, mucilage) but that
can still be lethal to marine animals or cause disruptions of other types.
Both toxic and non-toxic HABs represent potential threats to seawater desalination facilities.
Although toxins are typically removed very well by reverse osmosis and thermal desalination
processes (see Chapter 10), algal toxins represent a potential health risk if they are present in
sufficiently high concentrations in the seawater and if they break through the desalination
process. It is therefore important for operators to be aware when toxic blooms are near their
plants so they can ensure that the removal has indeed occurred (Chapter 3). High biomass
blooms pose a different type of threat, as the resulting particulate and dissolved organic
material can accelerate clogging of media filters or contribute to (bio)fouling of pretreatment
and RO membranes which may lead to a loss of production.
Impacts of HABs on desalination facilities are thus a significant and growing problem, made
worse by the lack of knowledge of this phenomena among plant operators, managers,
5
engineers, and others involved in the industry, including regulatory agencies. Recognizing
this problem, the Middle East Desalination Research Center (MEDRC) and the UNESCO
Intergovernmental Oceanographic Commission (IOC) organized a conference in 2012 in
Muscat, Oman, to bring HAB researchers and desalination professionals together to exchange
knowledge and discuss the scale of the problem and strategies for addressing it. One of the
recommendations of that meeting was that a “guidance manual” be prepared to provide
information to desalination plant operators and others in the industry about HABs, their
impacts, and the strategies that could be used to mitigate those impacts. With support from
the US Agency for International Development (USAID) and the IOC Intergovernmental
Panel for Harmful Algal Blooms (IPHAB), an editorial team was assembled and potential
authors contacted. For the first time, HAB scientists worked closely with desalination
professionals to write chapters that were scientifically rigorous yet practical in nature – all
focused on HABs and desalination. During the planning of this manual, it became clear from
an informal survey of the desalination industry that generally, HAB problems are far more
significant for seawater reverse osmosis (SWRO) plants than for those that use thermal
desalination. Both types of processes are very effective in removing HAB toxins (Chapter 10),
but the SWRO plants are far more susceptible to clogging of pretreatment granular media
filters and fouling of membranes by algal organic matter and particulate biomass.
Accordingly, the focus of this book is on SWRO, with only occasional reference to thermal
processes. Likewise, emphasis has been placed on seawater HABs, with reference to
estuarine and brackish-water HABs only when practices from those types of waters can be
informative or illustrative.
A brief synopsis of the book follows. Chapter 1 provides a broad overview of HAB
phenomena, including their impacts, the spatial and temporal nature of their blooms, common
causative species, trends in occurrence, and general aspects of bloom dynamics in coastal
waters. Chapter 2 describes the metabolites of HAB cells, including toxins, taste and odor
compounds. Methods for analyses are presented there, supplemented by detailed
methodological descriptions of rapid toxin screening methods in Appendix 2. As discussed in
Chapters 8 and 10, thermal and SWRO operations are highly effective in the removal of HAB
toxins, but plant personnel should have the capability to screen for these toxins in raw and
treated water to ensure that this removal has been effective. This would be critical, for
example, if the public or the press were aware of a toxic HAB in the vicinity of a desalination
plant intake and asked for proof that their drinking water is safe.
Currently, most desalination plants do not collect data on seawater outside their plants, so
they are generally unaware of the presence (now or anticipated) of a potentially disruptive
HAB. Chapter 3 provides practical information on the approaches to implementing an
observing system for HABs, describing sampling methods and measurement options that can
be tailored to available resources and the nature of the HAB threat in a given area. Appendix
4 provides more details on methods used to count and identify HAB cells during this process.
All are based on direct water sampling, but it is also possible to observe HABs from space –
particularly the high biomass events. Chapter 4 describes how satellite remote sensing can be
used to detect booms. The common sources of imagery (free over the Internet) are presented,
as well as descriptions of the software (also free) that can be used to analyze the satellite data.
It is relatively easy and highly informative for plant personnel to use this approach to better
understand what is in the seawater outside their plants. The cover of this guide provides a
graphic example of the incredible scale and resolution of this observational approach.
Chapter 5 discusses typical water quality parameters that are measured online or in feedwater
samples at desalination plants that could be used to detect blooms at the intake or evaluate
process efficiency in removing algal particulates and organics. Emerging parameters that also
6
show promise are examined to provide a resource for plant personnel. Chapter 6 looks at
desalination seawater intakes that are the first point of control in minimizing the ingress of
algae into the plant. A brief overview of siting considerations that may ultimately drive the
location of an intake is also provided.
One question asked frequently of HAB scientists is whether the blooms can be controlled or
suppressed in a manner analogous to the treatment of insects or other agricultural pests on
land. This has proven to be an exceedingly difficult challenge for the HAB scientific and
management community, given the dynamic nature of HABs in coastal waters, their large
spatial extent, and concerns about the environmental impacts of bloom control methods.
Chapter 7 presents a summary of the approaches to bloom prevention and control that have
been developed, and discusses whether these are feasible or realistic in the context of an
individual desalination plant.
Chapter 8 describes management strategies for HABs and risk assessment, including Hazard
Analysis Critical Control Point (HACCP) and Alert Level Framework procedures. Once a
HAB is detected, a wide range of approaches can be used to address the problems posed by
the dissolved toxins associated with those blooms. Chapter 9 presents many of these
pretreatment strategies and discusses their use in removing algal organic matter and
particulates to prevent filter clogging and membrane fouling. This is necessary to maintain
effective plant operation and avoid serious operational challenges for the reverse osmosis
step. The chapter covers common pretreatments such as chlorination/dechlorination,
coagulation, dissolved air flotation, granular media filtration, ultrafiltration, and cartridge
filtration, in addition to discussing issues experienced due to the inefficiencies of each
pretreatment on reverse osmosis.
Chapter 10 then addresses the important issue of HAB toxin removal during pretreatment and
desalination, and describes laboratory and pilot-scale studies that address that issue. Finally,
Chapter 11 provides a series of case studies describing individual HAB events at desalination
plants throughout the world, detailing the types of impacts and the strategies that were used
to combat them. These studies should be of great interest to other operators as they encounter
similar challenges.
The manual concludes with a series of appendices that provide images and short descriptions
of common HAB species (Appendix 1), rapid screening methods for HAB toxins (Appendix
2), methods to measure transparent exopolymer particles (TEP) and their precursors
(Appendix 3), methods to enumerate algal cells (Appendix 4), and reverse osmosis autopsy
and cleaning methods (Appendix 5).
Compilation of this manual was a major undertaking, requiring the cooperation of scientists
and engineers from multiple disciplines, including a number where interactions have been
rare in the past. We hope the accumulated material proves useful, and plan to keep this
document updated through time and readily available through the Internet. The Editors
welcome questions, comments, and suggestions that can make this compilation more useful
and accurate.
Donald M. Anderson
Woods Hole Oceanographic Institution
Siobhan F.E. Boerlage
Boerlage Consulting
Mike B. Dixon
MDD Consulting
7
Table of Contents

Foreword 3
Acknowledgements 4
Preface 5
Contributing Authors and Affiliations 13
Chapter 1. Harmful algal blooms Donald M. Anderson
1.1   Algal blooms 17
1.2   Harmful or toxic bloom species 20
1.3   Algal cell characteristics 22
1.4   Trends and species dispersal 32
1.5   Growth features, bloom mechanisms 34
1.6   Summary 41
1.7   References 42
Chapter 2. Algal issues in seawater desalination Philipp Hess, Loreen O. Villacorte,
Mike B. Dixon, Siobhan F.E. Boerlage, Donald M. Anderson, Maria D. Kennedy and Jan C.
Schippers
2.1 Introduction 53
2.2 Algal organic matter (AOM) and membrane fouling 53
2.3 Algal issues in thermal desalination plants 63
2.4 Marine and freshwater toxins 63
2.5 Taste and odor compounds 71
2.6 Detection techniques 71
2.7 Gaps and perspectives on analytical techniques 75
2.8 References 76
Chapter 3. Designing an observing system for early detection of harmful algal blooms
Bengt Karlson, Clarissa R. Anderson, Kathryn J. Coyne, Kevin G. Sellner, and Donald M.
Anderson
3.1 Introduction 89
3.2 Designing an observation system 90
3.3 Background information 90
3.4 Identifying existing infrastructure 93
3.5 Sampling methods 93
3.6 Identification and enumeration of HAB organisms 102
3.7 Satellite remote sensing 108
3.8 Transport and delivery of harmful algal blooms 108
3.9 Distributing warnings and information 110
3.10 Data storage and distribution 112
3.11 Facilities, equipment, and personnel 112
3.12 Summary 114
3.13 References 115
Chapter 4. Acquisition and analysis of remote sensing imagery of harmful algal blooms
Raphael M. Kudela, Richard P. Stumpf, and Peter Petrov
4.1 Introduction 119
4.2 Availability of data and software 121
9
4.3 Internet access to imagery 121
4.4 Software for processing satellite data 123
4.5 Algorithms used to detect blooms 124
4.6 Examples of algorithms 127
4.7 Summary for end-users 128
4.8 Useful links to satellite based ocean color data 130
4.9 References 130
Chapter 5. Harmful algal bloom-related water quality monitoring for desalination
design and operation Siobhan F.E. Boerlage, Loreen O.Villacorte, Lauren Weinrich, S.
Assiyeh Alizadeh Tabatabai, Maria D. Kennedy, and Jan C. Schippers
5.1 Intake feedwater characterization and water quality monitoring 133
5.2 Suitability of conventional online water quality parameters to detect
HABs 134
5.3 Overview of parameters to determine organic matter 136
5.4 Measuring biofouling potential 147
5.5 Fouling indices to measure particulate fouling potential 153
5.6 Summary 162
5.7 References 164
Chapter 6. Seawater intake considerations to mitigate harmful algal bloom impacts
Siobhan F.E. Boerlage, Thomas M. Missimer, Thomas M. Pankratz, and
Donald M. Anderson
6.1 Introduction 169
6.2 Intake options for SWRO desalination plants 171
6.3 Surface intake and screen options 172
6.4 Subsurface intake options 181
6.4 Siting of desalination seawater intakes 197
6.5 Summary 199
6.6 References 200
Chapter 7. Bloom prevention and control Clarissa R. Anderson, Kevin G. Sellner, and
Donald M. Anderson
7.1 Introduction 205
7.2 Bloom prevention 207
7.3 Bloom control 209
7.4 Summary 214
7.5 References 215
Chapter 8. World Health Organization and international guidelines for toxin control,
harmful algal bloom management, and response planning
Alex Soltani, Phillip Hess, Mike B. Dixon, Siobhan F.E. Boerlage, Donald M. Anderson,
Gayle Newcombe, Jenny House, Lionel Ho, Peter Baker, and Michael Burch
8.1 Guidelines and standards 223
8.2 Using guideline values 228
8.3 Australian drinking water guidelines regarding multiple treatment
barriers 228
8.4 Risk assessment for the presence of HABs 230
8.5 Alert level frameworks 240
8.6 Summary 247
8.7 References 247
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